Its not just about the money however. Society is mentally delicate and mentally programable, and we subconciously want these types of movies because its a way of venting our frustrations, hatred and contempt, and torturing or scaring fictional characters to death allows those involved to let it out, and those that watch it to feed off of it. I think this is true because there weren't nearly as many horror movies before 9/11, the war in iraq, etc.
Its not just about scaring an audiance. Are the movies actually scary? I'd say they're more disturbing than scary, and thats what they're tapping into when they make them.
If it was strictly because of the genre itself people would have cashed in sooner. They waited until now, when audiances were mentally ready to accept (and buy into) a flood of these types of movies, as they would identify more with them right now than they would any other genre.
I agree with you, it is about money. It always has been. But psychology has alot to do with it and the industry uses that to their advantage as well. When people think of "horror" movies, they think it automatically means "scary". Thats usually the first word that comes to mind. Horror is much broader than that and appeals to a wide range of taboo interests. And as such, it allows people to fantasize and be dark in dark times. Its a way of dealing with it, albeit inverted and perhaps unhealthy, at least mentally.
In retrospect, these movies encourage people to be sad, somber, and dark. They aren't trying to scare you and make sure you have a good time, they want you to buy into the attitude of it all. And thats not going to help anything. People don't want to give the entertainment business too much credit, but telivision and movies are the single greatest threat to the human condition that there is in this day and age. We're bombarded with many unhealthy images and we listen because its on tv.
This whole "dark" thing is just one peg on a wheel that the business is throwing out there right now because its ripe for cashing in on. Just watch, come summer, you'll see more comedy movies and an adventure/family movie or two come winter. Why? Because when something in congress gives, or your local government passes a bill in your favor, or the posture of the country changes for the better, you'll want to be happy again.
And what society wants, society gets. We won't be seeing so many horror movies after this phase is over, and they've milked it. Those horror movies that are made after the fact will have to rely heavily on pure audiance interest in the subject matter as the momentum will have shifted away from the genre itself.
Perhaps I'm just stating the unspoken obvious, but to leave it at "money" makes it more trivial than it really is. Are they, the ones making these movies taking it so lightheartedly? No. They're doing their damndest to keep your attention and interest because its their careers that are on the line, not yours.
Anyways, my point is I don't appriciate the way they've always taken advantage of key moments in history to make a buck. They did it with Vietnam and they're doing it again.